code: def afx_base():
      """Baseline - no momentum, beta=0.999."""
      hparams = afx_mimic_adam()
      hparams.optimizer_adafactor_beta1 = 0.0
      return hparams
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from tensor2tensor.models import transformer
  from tensor2tensor.utils import registry
label_desc: Use image node_id 4 for calling a global function with example usage: afx_base() and returns: hparams